Question

A bicycle wheel with a heavy rim is mounted on a lightweight axle, and one end of the axle rests on top of a post. The wheel is observed to presses in the horizontal plane. With the spin direction shown in figure11.111, does the wheel process clockwise or counter wise? Explain in detail, including appropriate diagrams.

Short answer

The torque points into the page and then the wheel process in clockwise direction.

Step-by-step solution

Definition of torque

Torque is defined as the force which causes the rotation of the object about an axis.

Find the torque point of the wheel

The direction of bicycle wheel rotation is as shown in the following figure.

The bicycle wheel on the axle behaves like a gyroscope with one of the axle on the vertical support. The wheel rotates in clockwise direction around its own axis with spin angular speed$\omega$ . The rotational angular momentum$\overrightarrow{L_{rot}}$of the wheel points horizontally but it is changing as the gyroscope processes. The forces that are acting on the system are force exerts by support and mass, at the center of the spinning wheel.

The translational angular momentum remains constant whereas the rotational angular momentum is change as$\frac{d{\displaystyle \overrightarrow{L}}}{dt}$ .

Thus, the torque points into the page and then the wheel process in clockwise direction.